diff --git a/inventory/group_vars/copr_back_aws b/inventory/group_vars/copr_back_aws
index dd0bd61a0a..d08c456389 100644
--- a/inventory/group_vars/copr_back_aws
+++ b/inventory/group_vars/copr_back_aws
@@ -38,4 +38,8 @@ nrpe_procs_crit: 2500
 nrpe_procs_warn: 2200
 root_auth_users: msuchy pingou frostyx praiskup schlupov
 spawn_in_advance: "true"
-tcp_ports: [22, 80, 443]
+tcp_ports: [
+    22, 80, 443,
+    # node_exporter/prometheus
+    9100,
+]
diff --git a/inventory/group_vars/copr_back_dev_aws b/inventory/group_vars/copr_back_dev_aws
index e568e1c88d..fd42bee4c4 100644
--- a/inventory/group_vars/copr_back_dev_aws
+++ b/inventory/group_vars/copr_back_dev_aws
@@ -41,4 +41,8 @@ messaging:
       username: copr
 root_auth_users: msuchy pingou frostyx praiskup schlupov
 spawn_in_advance: "false"
-tcp_ports: [22, 80, 443]
+tcp_ports: [
+    22, 80, 443,
+    # node_exporter/prometheus
+    9100,
+]